Quaternary glacial history of the Cantabrian Mountains of northern Spain: a new synthesis

Abstract

Abstract Recent dating and morphostratigraphical studies on glaciations in the Cantabrian Mountains permit a first reconstruction of the glacial evolution of the area. Located in the north of the Iberian Peninsula, between the Atlantic coast and the inner Mediterranean upland of the Duero basin, the mountains were occupied by ice fields as well as alpine and cirque glaciers during the Pleistocene. Five glacial phases can be distinguished, four belonging to the last Pleistocene glacial cycle and one historical in the Little Ice Age (LIA). Pre-maximum phases (predating the Late Pleistocene glacier maximum), identified at only three places, need more data before they can be more fully understood. The maximum glacial advance (RGM or SI) of the Pleistocene glaciers occurred at around 48–35 ka, before the global Last Glacial Maximum (LGM). A period of later glacial equilibrium (SII), which was a colder but drier phase, occurred just after the LGM (deglaciation ages ranging from 25 to 18 cal ka BP). The different glacial behaviour of the Cantabrian Mountains can be explained by orographic barrier effects: a more southerly circulation of atmospheric currents with more frequent southwesterly flows feeding snowfall towards the southern massifs. An ‘altitude stage’ (SIII) represented by small glaciers located in the cirques – and mainly those orientated to the north – exists in many massifs. Finally, LIA glaciers were only present in the Picos de Europa.